Muffler



Oct. 23, 19 45. TAYLQR 2,387,476

MUFFLER Filed Sept. 29, 1945 d? W *W A T TORNEYS Patented Oct. 23, 1945 UNITED STATES PATENT OFFICE,

MUFFLER Charles B. Taylor, Bufialo, N. Y.

Application September 29, 1943, Serial No. 504,248

3 Claims. I (Cl. 18l-58) This invention relates to a mufiler for silencing or suppressing the noise of air or gas discharged from internal combustion engines, air compressors, pneumatic motors and the like.

Devices heretofore employed for accomplish-;

ing this purpose usually included bafile means and restricted orifices which obstructed the path of the stream or air or gas to be quieted or interfered with the free flow of the same, but these have been found objectionable on account of.

the back pressure produced by such baille means and restricted orifices and the reduction in efficiency in the operation of the apparatus in connection with which such prior devices have been used.

devices and allow the exhaust gases to discharge L directly into the outer atmosphere through a conduit or piping which provided the shortest possible travel for the gases.

The object of this invention is to provide a mufile of this character whereby the effect of silencing or quieting the noise of exhaust gases is accomplished by means which are of compact and simple construction and which has no parts that would baffle or impede the flow of the gas and cause back pressure and impair power out-- 3 put of the apparatus with which the mufller is used.

With this end in view, this invention consists generally in so organizing the mufller that streams of the exhaust gas to be silenced are caused to whirl in opposite directions and in contact with each other and thus cause the pulsations or vibrations in gas to be subdued or eliminated and rendered virtually inaudible before the gas reaches the outer atmosphere.

In the accompanying drawing:

Fig. 1 is a perspective view of one form of mufller embodying this invention.

Fig. 2 is a longitudinal section of the same.

Figs. 3 and 4 are cross sections taken. re-

spectively, on the correspondingly numbered lines in Fig. 2.

In the following description similar reference characters indicate like parts in the several figures of the drawing.

It has The numeral It] represents an expansion or silencing chamber which receives under pressure the gas or air which is to be quieted or rendered inaudible from any source which discharges the same, such as the exhaust of an internal combustion engine, ai compressor, pneumatic motor or the like. Although this chamber may be formed within an enclosure, casing or housing of various forms the same preferably comprises a central section or body II of cylindrical form and two heads I 2, l2 arranged at opposite ends of the body and each having the form of a cone which tapers outwardly and lengthwise of the body and provided at its outer small end with an outlet or escape opening l3 which is arranged in line with the axis of the chamber and through which gas is discharged to the outer atmosphere after having been rendered noiseless.

The gas or air to be silenced is carried from its source into this expansion chamber by con ducting means which include a plurality of air or gas inlets which are arranged in pairs and the members of each pair opening through the wall or body of the expansion chamber in different parts of its periphery. Although any desired number of pairs of such gas or air inlet openings may be employed the particular embodiment of this invention shown in the drawing includes only one pair of such inlet openings and as there shown the front side of the body is provided with an upper air or gas inlet M which is arranged above the axis of the chamber and through which compressed gas or air is adapted to be delivered tangentially into the upper part of the chamber and caused to whirl circumferentially in the lat ter in one direction about the axis of the chamber, and a lower gas or air inlet [5 which is arranged below the axis of the chamber and through which compressed gas or air is adapted to be delivered tangentially into the lower part of the chamber and caused to whirl circumferentially therein in the opposite direction about the axis of this chamber.

These two gas or air inlets are preferably arranged in two different transverse planes of the expansion chamber so that the same are out of line or offset relative to each other in a direction lengthwise of the axis of the expansion chamber. In the preferred construction the inner ends I6 of the upper and lower openings It, IS are transversely in line and their outer ends ll terminate, respectively, at opposite ends of the cylindrical body of the housing, as shown in Fi 2.

Each of these inlets is also preferably of oblong rectangular form in cross section, the same being comparatively narrow crosswise of the expansion chamber and elongated in a direction parallel with the axis of the same, as shown in Fig. 2.

The gas or air to be rendered noiseless is carried from its source to the inlets of the expansion chamber by conducting means consisting preferably of a main conduit section I8 of cylindrical form in cross section and connected at its front or outer end in any suitable manner with the source" from "which the gas and air is supplied under pressure, and two branch pipes I9, 20 diverging from the rear or inner end of the main conduit to the upper and lower inlets I4,

I of the expansion chamber, each of said branchconduits having a longitudinally elongated ectangular terminal or spout 2| which eonnects with and corresponds to the shape of the respective inlet I4 or I5, and a cylindrical neck 22 connecting the elongated spout with the rear end of the main spout. 7

By these means the stream of ga's'orairissupplied by the main "conduit I8 in the form" of a body which is cylindrical in cross section and delivered into the upper'and lower parts or the expansion chamber in the Term of two 'j'ets each of whichis of flattened form lengthwise-of the expansion chamber.

lhe cross sectional area of the main conduit I8 is equal to or substantially equal to the com bined' cross sectional area of the two outlets I3 of the expansion chamber so that the volume of chamber through'the outlets" I3 in e ual volume.

and at the same pressure and rate of s eed. The cross sectional area of the expansion chamber In is, however, many times larger "than that of the main supply conduit I8 andthe'ou'tlets I3, whereby the more or less compressed gas or air entering the expansion chamber under pressureisfirst permitted to expand fully and thenagaincompressed before it can escape through the outlets I3 of the expansion chamber.

As'the gas or air under pressure is supplied'by the main conduit I8 the same is divided "and"de livered tangentially by the spouts 2|, 2| in the form of two smaller streams through the inlets I4 and I5 into the upper and lower'p'a'rts of the expansion chamber. As each division of the streams of gas or air enters the expansion chamber the same is whirled circumferentially therein around the axis of this chamber, the one entering the upper inlet I4 moving in an anti-clockwise direction, as shown in Fig. 3, and the one entering the inlet I5 moving in a clockwise direction,

' as shown in Fig. 4, during which movement of inner opposing parts "of these streams" contact each other and produce a frictional engagement between the same which has the efie'ct of retarding the whirling or rotation of the same in opposite directions and also to retard the vibration or pulsation of the same and thus further quiet the noise which otherwise would be produced.

As the two opposite whirling streams or gas or air in the expansion chamber rub against each other and also expand the outer parts of these whirling streams graduall work lengthwise outwardly in the expansion chamber toward the conical or tapering heads of the same in a form resembling that of a spiral conical snail, whereby the streams of gas or air are retarded and compressed while in a non-pulsating or non-vibrating expansion chamber it'gradually'ceases to vibrate and avoids producing any appreciable noise and at this time the gas or air virtually does not pro- -duce any back pressure so that the elimination of noise is efiected without lowering the efiiciency of the apparatus from which the gas or air to be silenced-is derived.

It will be seen that an essential feature of the invention resides in the location of the two tangential inlet tubes 2 I, 2I so that one of these tubes extends tangentially 'from'the' she'll H in one angular direction and so that the other of these tubes extends tangentially from the shell' in'the opposite angular direction thereby to cause the several 'g'as streams" from the several tubes to whirl cii'cumferentially in opposite directions and in contact with each other for eliminating noise producing pulsations therefrom. The term angular direction; as used above and inthe accompanying'claims, is used'in the geometric sense with reference to the shell to which the inlet tubes are tangential. in this sense one of'the-tubes 2I extends tangentially and'clockwi'se from'th'e sh'ell and the other tube 2| extends in the opposite angular direction or counterclockwise from the shell.

Moreover, the onset of silencing or quietingthe gas or air is produced without the use of any bafiie means in the path of the gas or air streams for obstructing the flow of the same, thus simplifying the mufiler, reducing its cost of manufacture and also permitting of making the same compact so that it can be readily installed in places where only a limited amount of space isavailable.

I claim as my invention:

1. A muffler for silencing the noise of exhaust gases from internal combustion engines and the like, comprising a shell providing a tubu-lar'chamber having an axial outlet, and a plurality 'of -inlet tubes for gas under pressure extending tangentially from said shell and opening tangentially into the periphery of said chamber at different circumferential parts of the same, and-one of said tubes extending tangentially from said shell in one angular direction and another of said tubes extending tangentially from said shell in the opposite angular direction for causing the incoming gas streams from the several tubes 'to whirl circumferentially in opposite directions and in contact with each other for eliminating noise producing pulsations therein.

A mufiier for silencing the noise of exhaust gases from internal combustion engines and'the like; comprising a shell providing a tubular chamber having an axial outlet and a plurality of inlet tubes for gas under pressure extending tangentially from said shell and opening tangentially into the periphery of said chamber at different circumferential parts of thesame, and one ofsaid I tubes extending tangentially from said -shellin one angular direction and another of rsaid tubes extending tangentially from said shell in the opposite angular direction for causing theincommg gas streams from the several t'ubesto 'whirrcircumferentially in opposite directions and in contact with each other for eliminating noise producing pulsations therein-and said tubes being arranged in transverse planes which are side by side lengthwise of the axis of said chamber.

3. A mufller for silencing the noise of exhaust gases from internal combustion engines and the like, comprising a shell providing a tubular chamber having an axial outlet, and a plurality of inlet tubes for gas under pressure extending tangentially from said shell and opening tangentially into the periphery of said chamber at difierent circumferential parts of the same, and one of said tubes extending tangentially from said shell in one angular direction and another of said tubes extending tangentially from said shell in the opposite angular direction for causing the incoming as streams from the several tubes to whirl circumferentially in opposite directions and in contact with each other for eliminating noise producing pulsations therein, the area of said inlet tubes being substantially the same as the area of said outlet.

CHARLES E. TAYLOR. 

